<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
		<% 
		String s1 = request.getParameter("a");
		String s2 = request.getParameter("b");
		String s3 = request.getParameter("c");
double area = (Integer.parseInt(s1)+Integer.parseInt(s2))*Integer.parseInt(s3)*0.5;
		%>
		梯形的上底是<%=s1 %><br>
		梯形的下底是<%=s2 %><br>
		梯形的高是<%=s3 %><br>
		梯形的面积是<%=area %><br>
</body>
</html>